AstronomyPicture of the Day—20181202

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2018 December 29

AcrossCorona Australis

ImageCredit & Copyright: Fabian Neyer

Explanation:Cosmic dust clouds are draped across a rich field of stars in this broadtelescopic panorama near the northern boundary of Corona Australis, theSouthern Crown. Less than 500 light-years away the denser clouds effectivelyblock light from more distant background stars in the Milky Way. The entirevista spans about 5 degrees or nearly 45 light-years at the clouds' estimateddistance. Toward the right lies a group of bluish reflection nebulae catalogedas NGC 6726, 6727, 6729 and IC 4812. The characteristic blue color is producedas light from hot stars is reflected by the cosmic dust. The dust also obscuresfrom view stars in the region still in the process of formation. Smalleryellowish nebula NGC 6729 surrounds young variable star R Coronae Australis.Below it are arcs and loops identified as Herbig Haro (HH) objects associatedwith energetic newborn stars. Magnificent globular star cluster NGC 6723 isabove and right of the nebulae. Though NGC 6723 appears to be part of thegroup, its ancient stars actually lie nearly 30,000 light-years away, farbeyond the young stars of the Corona Australis dust clouds.